1 / 13

Evolutionary Stigmergy for Co-operative Agent Teams: Heterogeneity and Division of Labour

Explore evolving software agent teams using stigmergy and evolved heterogeneity. Focus on team composition, agent representation, and evolutionary methods. Discuss biological insights and compare methods from literature. Experiment with tasks and specialization. Analyze results through biological metaphors for further research opportunities.

rania
Télécharger la présentation

Evolutionary Stigmergy for Co-operative Agent Teams: Heterogeneity and Division of Labour

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Solving the Division of Labour Problem Using Stigmergy and Evolved Heterogeneity Emyr James Dr. Richard Watson Dr. Jason Noble

  2. Research Interest • Evolving Co-operative Teams of Software Agents • How to represent an agent? • How should we put agents together in a team ? • For a given team composition and agent representation how should we do the evolution? • Focus on Engineering Methodology • May be able to give insight into some Biological questions along the way.

  3. Examples from the Literature • 2 Main methods • Homogenous teams of clones (Quinn, Floreano) • Heterogenous teams built from co-evolved sub-populations (Uchibe et al.) • Other methods – Chromosomal Model (Andre and Teller), Legion System (Bongard)‏ • Agent and Team types fixed a priori • Is it possible for the amount of heterogeneity to be evolved ?

  4. Search for a Suitable Task • Simple team task based on santa fe ant in GP • Ant can execute following commands... if_food_ahead, progn2, progn3, left, right, move. • Controller is GP tree made up of these primitives

  5. Demonstration

  6. Removing Stigmergy • Task changes from Mowing to Spraying. • No possibility of stigmergy. Added specialisation command IfAgentn and an identifying tag for each individual (Tanev et al. got there first....)‏

  7. Experimental Design • Have 2 tasks, analogous to Mowing and Spraying. • Mowing task allows stigmergy so no need for specialisation. • Only way to divide labour in Spraying is through specialisation. • Will evolution use an appropriate amount of specialisation for the two tasks ?

  8. Method • 4 Experiments carried out, two for each task. Specialisation commands turned on and off. • In each run, population was 1000. All members initialised with trees of size 1 (i.e. only terminal commands). Teams of size 6. • Undergo process of evolution utilising crossover and mutation, underlying GA was Deterministic Crowding due bloat mitigation • 26 runs, each allowed 2 hrs cpu time. Data analysed to pick out best of run.

  9. Results

  10. Fitness

  11. Biological Metaphors • Two biological metaphors fit this scheme and suggest ways in which to take this work further • Multi-cellular organism with differentiated cells. • Polyphenism

  12. Further Work • See how far the multicellularity metaphor can go – change from id for each agent to agent classes. Hierarchical differentiation ? • Polyphenism – talk by Rob Mills yesterday. • Vary team size. Bigger teams require more co-ordination. Will the degree of specialisation reflect this ? • Compare this approach with the purely clonal and purely heterogeneous methods from the literature.

  13. Conclusions • Have shown that varying amounts of specialisation is evolved to suit the task. • This method good for situations where agents have some common behaviour but need some specialisation under certain circumstances. • Biological metaphor – clonal differentiated cells – team can be considered to be a multi-cellular organism.

More Related